Any president's critics can have a field day with presidential trips and vacations, noting the costs, the huge entourages and (as a 21st-century twist) the carbon footprint. Such snark gets doubled if some sort of crisis happens while the president is on the move-"Why isn't he in the White House overseeing the crisis at hand rather than [fill in low-priority minutia of the trip]"
This week, it got redoubled with the president in Cuba. No, it wasn't Obama's finest hour, and I'll leave it at that for the moment. However, anything short of Obama kicking Raul Castro in the short and curlies and going for a take-down would have been seen as feckless catering to fellow leftists to his ardent critics.
The representative sample comes from Dr. Krauthammer-"...he does this ideological holiday trip in Cuba while the world burns." Pray-tell what was he supposed to do in Washington that couldn't have been done on a secure phone elsewhere?
One of the takeaways of the recent bombing is that Belgian and European security can't keep up with the amount of suspected terrorists. The response to that would be to somehow both fund and recruit a whole crop of investigators and intelligence folks to close that gap, but that's something that isn't going to happen at the snap of Super Prez's fingers. It would require getting authorization from Congress (unless you want him freelancing on this one), getting cooperation from European officials if we're doing police work for them, and lastly hiring the people needed to get the job done.
Oh, and that assumes that you would actually want to do that. Keeping that level of tabs on European Muslims seems to run counter to Obama's leftist DNA. If the world is burning, a president who wants to get a stick and some marshmallows for some s'mores isn't going to help, wherever he might be.